“There are plenty of ships and plenty of cargo to come into the island,” said Mark Miller, a spokesman for shipping company Crowley, which has 3,000 containers of supplies in the US territory.

“From there, that’s where the supply chain breaks down — getting the goods from the port to the people on the island who need them,” he told Bloomberg News.

Around 9,500 containers carrying supplies remained stuck at the Port of San Juan on Thursday, while the island’s 3.4 million residents faced another day of food, fuel and water shortages, waiting in hours-long lines to buy basic items.

“Really, our biggest challenge has been the logistical assets to try to get some of the food and some of the water to different areas of Puerto Rico,” Gov. Ricardo Rosselló told MSNBC.

Many roads on the island remain washed out or blocked by debris, and authorities have had trouble reaching out to truck drivers who can deliver supplies.

“When we say that we don’t have truck drivers, we mean that we have not been able to contact them,” Rosselló said.

Earlier in the day, Sen. Marco Rubio said that only the Defense Department could manage the logistics of getting aid distributed to residents quickly.

“The only people who can restore it, who have the capacity to do so quickly in the short term and then turn it over to the authorities there in Puerto Rico, is the Department of Defense,” the Florida Republican told CNN.

“We need someone in charge of that with the know-how of logistics, with the capability to restore logistics and with the authority to make decisions quickly without having to check with 18 agencies.”

The Trump administration has been facing criticism over its response to the unfolding humanitarian crisis in Puerto Rico, with some charging that it was slow to react.

“The federal response has been a disaster,” said lawmaker José Enrique Meléndez, a member of Rosselló’s New Progressive Party. “It’s been really slow.”

But Trump’s advisers pushed back against those accusations Thursday, with acting Homeland Security Secretary Elaine Duke saying that she was “very satisfied” with the federal government’s response and that “the relief effort is under control.”

“The full weight of the United States government is engaged to ensure that food, water, health care and other lifesaving resources are making it to the people in need,” she said.

Of the island’s 69 hospitals, 44 are operational, officials said. Forty-four percent of Puerto Ricans remain without drinking water and most of the island is still without power.

Pastor Irving Figueroa of the Wesleyan Church in the northern municipality of Guaynabo said islanders were desperate for food, water and medicine.

“Parents with two or three kids at home, they need water, and they need milk and the basics in order to help their kids,” he told The Post. “This is a catastrophic situation.”

Figueroa — whose church has been working with World Hope International to distribute supplies such as water filters, tarps and solar chargers — said people have been spending 10 to 11 hours in line just to buy gas.

“There are 500 to 700 people all in line to get water from the places that the government are providing,” he explained.

“This is the worst situation in our history. It’s like being in a military combat situation.”